Effects of Nitric Oxide on the Germination of Wheat Seeds and Its Reactive Oxygen Species Metabolisms Under Osmotic Stress

Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).

Effect of Different Treatment on Seed Germination of Echinochloa crus-galli

The effect of different treatment on seed germination of Echinochloa crusgalli was investigated in this study. The results showed that GA3, concentrated sulfuric acid, KNO3, NaOH and temperature treatments all could promote the germination of E. crus-galli seeds, but there were great differences in the promoting effect. Seed soaking with 1 000-1 500 mg/L of GA3 for 24 h and seed soaking with concentrated sulfuric acid for 15-20 min all maintained the germination rate of E. crusgalli seeds higher than 70.0%; 1.5% NaOH made the germination rate of E. crusgalli seeds up to 93.7%, but higher-concentration NaOH significantly reduced the germination rate of E. crus-galli seeds; KNO3 treatment showed certain promoting effect on germination of E. crus-galli seeds, but the effect was not ideal, i.e., the germination rate was lower than 35.5%; 20-25 ℃ temperature treatment could effectively promote the germination of E. crus-galli seeds, and the germination rate ranged from 68.2% to 75.8%.

Effect of pre-soaking and pre-chilling treatments on seed germination of Pinus roxburghii provenances from western Himalaya, India

After subjecting the seeds to GA3 and H2O2 treatments for 24 h and chilling at 2-3℃ for a period of 15 days, we conducted the seed germination tests for 21 different seed sources ofPinns roxburghii from western-central Himalaya under laboratory conditions at various temperatures viz., 20℃, 25℃ and 30℃ inside a seed germinator. The results reveal that the soaking of seeds in H2O2 （1% v/v） and GA3 （ 10 mg.L^-1） solutions manifested 82.39% and 78.19% germination, respectively whereas untreated seeds exhibited 70.79% average germination. Both GA3 and H2O2 treatments caused an appreciable shortening of the germination period by 8 days and 10 days, respectively. Moist-chilling did improve the rate and percentage of germination when germinated at 20℃ over 21 days; however total germination was not affected at temperatures 25℃ and 30℃, Although the seeds of P. roxburghii germinate well due to lack of dor- mancy, the increasing demand for large quantities of seeds of P. roxburghii for reforestation programmes make pre-sowing treatments useful in improving the rate and percentage of gemaination.

Beneficial effects of cold-moist stratification on seed germination be- haviors of Abies pindrow and Picea smithiana

A study was conducted to evaluate the effect of GA3, moist-chilling and temperature on seed germination ofAbies pindrow and Picea smithiana from five different provenances. Seeds were soaked in GA3 （10 mg·L^-1） for 24 h, then chilled at 3-5℃ for 15 days. Four temperature regimes viz. 10℃, 15℃, 20℃ and 25℃ were used for stimulating seed germination. Results showed that soaking and chilling significantly increased germination percentage. The germination percentage was highest at 10℃. Overall results showed that soaking seeds in GA3 （10 mg·L^-1） for 24 h, moist chilling for 15 days, and germinating at 10℃ produced an effective germination in both the species studied. The statistical analysis of the data proclaimed significant effect of treatment, temperature, provenance and treatment with temperature interactions on seed germination.

外源激素对沙米(Agriophyllum squarrosum)种子萌发的影响

为了筛选促进沙米种子萌发的最佳外源激素处理方法,用不同浓度的赤霉素(GA_(3)、GA_(4+7))和ABA合成抑制剂氟啶酮(FL)进行浸种实验,分析外源激素浸种浓度和浸种时间对沙米种子萌发的影响。结果表明:(1)浓度为1.6 g/L GA_(3)、0.4 g/L GA_(4+7)和5.0μmol/L FL浸种效果最好,发芽率分别为93%、82%和100%,总体效果FL>GA_(3)>GA_(4+7)。(2)在适宜浓度下,0~24 h浸种时间内沙米种子的发芽率均随着外源激素浸种时间的延长呈增加趋势,浸种24 h发芽率最高。(3)在相同浸种时间下,FL浸种萌发率均高于GA_(3)和GA_(4+7),FL能更快破除种子休眠,促使种子快速萌发。总之,外源激素浸种不仅能提高沙米的萌发率,也极大地缩短了沙米种子的萌发进程。

壳聚糖对冬小麦种子萌发过程中生理活性影响

以一定规格不同浓度的壳聚糖处理小麦种子 ,可提高种子萌发过程中胚乳 GA3含量和α-淀粉酶活性 ,并可不同程度地提高种子发芽势、发芽率、幼苗株高、干物重等。且壳聚糖浓度效应明显。其处理种子的最佳浓度范围为 4～ 6 mg/

青钱柳种子休眠与萌发的研究

青钱柳种子的种壳占种子风干重 85.9%。种子具有透水性。浓硫酸处理 9小时后 ,种壳减轻重量约占种子总重量的 2 8.8% ,既减弱了种壳的机械束缚力 ,又增加了种子透气性。酸蚀 9.5小时的种子 ,经 50 0 mg/ LGA3 溶液浸种 ,并用拌有 50 0 mg/LGA3 溶液的湿沙层积一冬 ,发芽率达到 87.5% ,而风干种子则颗粒未发。破除休眠后种子的萌发温度 ,以 2

银钟花种子休眠和萌发的初步研究

银钟花种子种皮约占种子风干重 93%。种子透水性良好。大粒种子酸蚀处理 4 .5小时后 ,重量减轻 6 2 .5 %。小粒种子则以 1.5小时为好。经酸蚀处理后的种子 ,再用 5 0 0 mg· L- 1 GA3处理后 ,在室外层积一冬 ,发芽率可达 72 .9% ,而风干种子则颗粒未发。破除休眠的种子 ,萌发温度以 2

长柄双花木种子休眠与萌发的初步研究

长柄双花木种子的种皮占种子风干重 6 0 .2 %。种子透水性良好。浓硫酸处理 11h后 ,可使种皮减轻重量约占种子总重量的 11.32 % ,加强了种子的透气性并减弱了种皮的机械束缚力。酸蚀 11h的种子 ,与拌有 5 0 0 mg·L- 1 GA3湿沙相混并经一冬层积后 ,可获 38.9%的出苗率 ,而对照则颗粒不发。破除休眠后种子的萌发温度以 2 0℃为宜。

四种化学物质处理对无刺含羞草种子发芽率的影响

无刺含羞草种子经四种化学物质处理后的萌发实验表明 ,5% HCl溶液对种子萌发几乎无影响 ;0 .2 % KNO3 溶液浸泡 1～ 2 d促进种子萌发 ;Na OH和赤霉素溶液在浓度较低 (分别为 0 .1～ 0 .2 5mg/ L和 0 .5% )时适当延长浸泡时间能促进萌发 ,浓度较高浸泡时间又较长对萌发无影响甚至抑制萌发。四种化学物质对种子萌发的影响与溶液的浓度及浸泡时间有关。

GaAs、Ga^（3＋）和As（V）对蔬菜种子萌发生理影响研究

通过培养试验，研究了ＧａＡｓ、Ｇａ^（３＋）和Ａｓ（Ｖ）对小白菜和菠菜种子发芽势、发芽率和胚芽生长等形态指标以及过氧化氢酶、多酚氧化酶活性的影响。结果显示，低浓度毒物（ＧａＡｓ为１０─５０ｍｙ／Ｌ，Ｇａ^（３＋）为５０─１００ｍｇ／Ｌ，Ａｓ（Ｖ）为１０ｍｇ／Ｌ）对种子的萌发有一定刺激促进作用，高浓度下则为明显的抑制作用；菠菜种子对毒物的敏感性高于小白菜种子；毒物对种子萌发生理的毒性大小顺序为Ａｓ（Ｖ）＞ＧａＡｓ＞Ｇａ^（３＋），表明其毒性主要与Ａｓ有关。

赤霉素浸种与层积时间对距瓣尾囊草种子萌发的影响

以距瓣尾囊草种子为实验材料,采用培养皿发芽法,研究不同浓度赤霉素浸种与层积时间对种子萌发的影响。结果表明:种子具有休眠特性,层积能够促进种子的萌发,时间越长效果越好。层积前用赤霉素浸种处理可显著提高种子发芽率和发芽势。用浓度400 mg·L-1的赤霉素对种子浸泡24 h后层积60 d的萌发效果最好,可使种子的发芽率和发芽势达到83.91%和51.60%。

外源赤霉素对东北刺人参种子萌发的影响

外源赤霉素(GA3 )对处于不同处理阶段的东北刺人参种子萌发的影响的研究结果表明:在种子处理前期用一定浓度的GA3 处理种子,对种子萌发没有明显的促进作用。在较长处理时间后,用GA3 处理可以明显提高种子的发芽率。

提高团花种子萌发率的方法

温水浸种可以提高团花种子种皮的透水性 ,促进种子萌发 ,提高发芽率 ,其中以 5 0℃、 6 0℃的温水处理效果最好 ,温水处理时间长短无显著差异 ,采用不同浓度的GA3 处理团花种子可以打破种子休眠 ,促使种子萌发 ,且以 10 0～ 2 0 0 μl/l的浓度处理效果较好。

滇青冈种子的萌发

比较 3种打破滇青冈种子休眠方法的结果表明 ,经 4 0℃处理后的效果最好 ,发芽率达 74 .5 %。 10 0mg·L-1的赤霉素浸种处理的次之 ,发芽率为 70 .2 %。种子种皮切伤和去除种皮后 ,发芽率增大 ,分别为 96 .0 %和 95 .0 % ,并提早 5d萌发。种子抑制物质实验的结果显示 。

盐条件下不同植物生长调节剂对冰菜种子萌发的影响

冰菜是一种具有极强耐盐性的新型蔬菜,具有极高的营养价值和保健作用。本文针对冰菜种子萌发率低的问题,采用不同浓度的赤霉素(GA_3)、水杨酸(SA)和抗坏血酸(Vc)等3种植物生长调节剂在盐条件下处理冰菜种子。研究结果表明:冰菜种子萌发的最适盐浓度为10 g·L^(-1)。在此盐度下,若添加10 mg·L^(-1)的GA_3,冰菜种子的发芽率最高可达77.3%;也可添加20 mg·L^(-1)的水杨酸或20 mg·L^(-1)的抗坏血酸,都会对冰菜种子萌发具有明显的促进效果。

不同天然居群小檗种子萌发障碍因子研究

以西天山野果林霍城居群、新源居群和特克斯居群黑果小檗以及特克斯居群红果小檗种子为试验材料,研究了4组野生小檗种子生物学特性、吸水特性以及去种皮、低温层积和不同浓度GA_3处理对小檗种子休眠与萌发特性的影响,结果表明:(1) 4组野生小檗种子的吸水率均表现出逐渐增加的趋势,黑果小檗种子与红果小檗种子吸水率差异不明显,其种皮透水透气性相似;(2)霍城居群、新源居群和特克斯居群黑果小檗种子的种皮对萌发存在强烈的抑制作用;而新源居群红果小檗种子的种皮抑制作用不明显;(3) 4℃低温层积处理对4组野生小檗种子萌发影响很大,随层积时间的增加小檗种子发芽率均逐渐提高,3组黑果小檗种子层积90 d时,休眠基本被解除;红果小檗种子层积30 d时,休眠基本被解除;(4)浓度为200 mg·L^(-1)的GA_3溶液处理可显著提高4组小檗种子发芽率,浓度过高或过低均会对小檗种子萌发起到抑制作用。层积60 d时霍城居群、新源居群和特克斯居群黑果小檗去种皮种子用200 mg·L^(-1)的GA_3溶液处理2 h后,发芽率分别为85. 00%、83. 33%和86. 67%;红果小檗层积15 d时去种皮种子用浓度为200 mg·L^(-1)的GA_3溶液处理后,发芽率可达86. 67%。研究结果将为今后野生小檗的种质资源保护,利用及可持续发展提供技术支持和科学依据。

腐胺在GA_3促进水稻种子萌发中的作用

以水稻盐粳１８７种子为材料，初步研究腐胺（Ｐｕｔ）在ＧＡ３促进种子萌发中的作用。结果表明：种子吸水后４８ｈ内源ＧＡ１＋３、Ｐｕｔ含量和α－淀粉酶活力增强密切相关。外源ＧＡ３（０．１４ｍｍｏｌ／Ｌ）在促进种子大量萌发和α－淀粉酶合成之前（１８ｈ）首先诱导Ｐｕｔ合成高峰。使用无胚半种子的进一步实验证明，外源ＧＡ３可诱导内源Ｐｕｔ含量增加，外源Ｐｕｔ可增强α－淀粉酶活力。

4种铁线莲属植物种子萌发特性

本研究以转子莲(Clematis patens)、棉团铁线莲(C.hexapetala)、大叶铁线莲(C.heracleifolia)和齿叶铁线莲(C.serratifolia)4种种子为材料,研究激素及浸种温度对其萌发的影响。结果表明,转子莲最适浸种温度为35℃,棉团铁线莲、大叶铁线莲和齿叶铁线莲最适浸种温度均为25℃,其发芽率分别为24.87%、93.24%、80.94%和68.21%。400mg·L^(-1)赤霉素(GA3)有利于转子莲种子萌发,其发芽率为19.17%;棉团铁线莲在5mg·L^(-1)细胞分裂素(6-BA)和500mg·L^(-1) GA3中萌发情况最好,其发芽率为90.56%和90.50%;10mg·L^(-1)6-BA能显著促进大叶铁线莲种子萌发,其发芽率为88.26%;5mg·L^(-1) GA3有利于齿叶铁线莲萌发,其发芽率为53.00%。

不同激素对香果树种子发芽特性与呼吸速率的影响

为更好地促进香果树繁殖提供参考,对香果树种子进行不同浓度的赤霉素(GA_3)和吲哚乙酸(IAA)的浸泡试验,在光照条件和暗环境下,测定香果树种子的发芽率和萌动呼吸速率,以分析不同激素和光照条件对香果树种子发芽的影响。结果表明:在光照条件和暗环境下,赤霉素对香果树种子发芽均具有促进作用,均以GA_3浓度400mg/L处理的发芽率和呼吸速率最高,暗环境种子发芽率和呼吸速率分别比光照条件高8.00%和1.28mg/(g·h)。吲哚乙酸不利于香果树种子的萌发,经IAA处理的香果树种子发芽率显著低于冷水20℃浸泡(CK1)和热水55℃浸泡(CK_2),暗环境下CK1和CK_2发芽率分别比100mg/L IAA处理高46%和51%,光照条件下分别高57%和52%。香果树光照条件下发芽率与呼吸速率呈正相关关系,与暗环境下发芽率和呼吸速率呈显著相关关系;光照条件下呼吸速率与暗环境下发芽率和呼吸速率呈显著正相关关系,暗环境下发芽率与呼吸速率呈极显著相关关系。适当浓度的GA_3浸种可以提高香果树种子的呼吸速率,加快种子内部贮藏营养物质的分解,提高发芽速度,以赤霉素浓度为400mg/L处理效果最佳。